3D Printers for Woodworkers

CRAFT & HOBBIES / Woodwork “A boon for the casual hobbyist and serious craftsperson alike.”

—Publishers Weekly

Make your own parts and tools — and save money!

3D printing is the ideal tool for the traditional woodworker. You can save hundreds or even thousands of dollars by making your own 3D-printed parts and tools, custom-made for your unique needs.

3D Printers for Woodworkers is the perfect introduction to 3D printing, covering: • How 3D printing works • How to pick the right 3D printer for your needs • How to use 3D printer software • How to print tools and hardware such as jigs, clamps, drawer pulls, hinges, slides, and shims Comprehensive and user-friendly, 3D Printers for Woodworkers is the ideal book for all woodworkers who want to save time and money while producing exceptional results.

ISBN 978-1-933502-03-8

$17.95 US

9 781933 502038

51795

3D PRINTERS FOR WO O DWO R K E R S A S H O RT I N T R O D U C T I O N

Henry Doolittle

Fresno, California

3D Printers for Woodworkers Copyright Š 2020 by Henry Doolittle. All rights reserved.

All images courtesy of the author unless otherwise noted.

All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by an information storage and retrieval system, without written permission from the publisher.

Published by Linden Publishing 2006 South Mary Street, Fresno, California 93721 (559) 233-6633 / (800) 345-4447 WoodworkersLibrary.com Linden Publishing and Colophon are trademarks of Linden Publishing, Inc. book design by Andrea Reider cover design by Tanja Prokop, www.bookcoverworld.com Linden Publishing titles may be purchased in quantity at special discounts for educational, business, or promotional use. To inquire about discount pricing, please refer to the contact information below. For permission to use any portion of this book for academic purposes, please contact the Copyright Clearance Center at www.copyright.com.

ISBN 978-1-933502-03-8 135798642 Printed in the United States of America on acid-free paper.

Library of Congress Cataloging-in-Publication Data on file.

Ta b l e o f C o n t e n t s Foreword Chapter 1 A History of 3D Printing . . . . . . . . . . . . . . . . 1 Chapter 2 Basics of 3D Printing . . . . . . . . . . . . . . . . . . 11 Chapter 3 Types of 3D Printers . . . . . . . . . . . . . . . . . . . 19 Chapter 4 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Chapter 5 What to Look for in a 3D Printer . . . . . . . . 41 Chapter 6 Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Chapter 7 Filaments . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Chapter 8 The Print Process . . . . . . . . . . . . . . . . . . . . . . 65 Chapter 9 What Can Go Wrong . . . . . . . . . . . . . . . . . . 75 Chapter 10 Print Projects . . . . . . . . . . . . . . . . . . . . . . . . . 81 Chapter 11 Finish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 Index

Foreword

3D Printers for Woodworkers offers a compressive look at the history, development, and usage of 3D printers. To understand a tool, it helps to understand its history: how it came about, how it was used, and how it evolved to its use today.

Once the history lesson is done, Henry Doolittle dives into the nitty-gritty of 3D printing. What types of printers are there? Which 3D printer is best for particular applications?

What filaments do you need for your particular project? He answers all these questions along with discussing where to place your printer and how to calibrate the print head. Then Henry gives you projects to test your printer’s capabilities.

He shows successful prints and even more importantly shows you prints that go wrong. Then he explains in detail how to avoid the issue or fix it.

History and education are great, but a book on 3D printing had better share some useful and fun projects, and Henry does not disappoint. He provides well over a dozen projects for the woodworker. From a center finder to a pocket screw jig to a corner jig, Henry lays out the steps and tips needed to become a competent 3D craftsman.

If you want to test out this new technology, I highly recommend you purchase a copy of 3D Printers for Woodworkers as your introduction to the world of 3D printing. —Tim Yoder, nationally awarded television producer, photographer, editor, and longtime woodturner

Chapter 2

Basics of 3D Printing

With 3D printing, complexity is free. The printer doesn’t care if it makes the most rudimentary shape or the most complex shape, and that is completely turning design and manufacturing on its head as we know it. —Avi Reichental, CEO, 3D Systems

I

magine you want to make a toy for your new daughter.

You take a glue gun to draw a picture of a frog using a low-temperature plastic. You start drawing the frog using the material you push out of the glue gun. It works but not very accurately. You decide to use a mechanism like the inside of an Etch A Sketch to control how you lay out the plastic. You use two knobs to control the movement of the glue gun. When you complete one layer, you raise the glue gun and start the next layer. Next you decide that you can add stepper motors to the knobs and thereby move (step)

3D PRINTERS FOR WOODWORKERS

the motors to control distance and direction. Add a controller and you can tell the motors to move x 10 steps (along the x axis) and y 5 steps (along the y axis). This is how S. Scott Crump developed the first FDM printer.

In the world of computer-aided manufacturing (CAM), you have both additive manufacturing and subtractive manufacturing. We are used to and expect subtractive manufacturing: the use of saws, mills, planners, lathes, and other tools to remove stock to get to the final size and shape. We cut, grind, sand, and remove material as needed.

If you make cabinets, you start with a sheet of plywood. You cut it into smaller panels using saws. You gradually remove material and reduce the size of the original panel, taking the smaller panels to the next step, and so on.

CNC routers, for example, use a process of subtractive manufacturing. You start with a block of material and remove that which is not needed. With a CNC router you place the sheet of plywood on the bed and provide the instructions to the router. The router cuts the individual panels, drills the holes, and sets them up for sanding and glue-up. The CNC router is a tool just like any other tool in the shop.

The difference is the level of automation and the amount of upfront effort required.

The CNC router requires CAD (computer aided design) software, to set up the layout of the cuts and holes. And computer aided manufacturing (CAM) software provides the G-code (G-code is a programing language that tells the CNC mill what to do) needed to direct the movement of the router’s head. The same is true for 3D printers.

All 3D printers use a process called additive manufacturing, as opposed to the process of subtractive manufacturing. The normal subtractive process of building a wooden bowl is to take a block of wood and remove the material that isn’t needed. A 3D printer works by adding material as needed to create the bowl, not unlike the 12

B asics of 3 D P rintin g

process of segmented turning, whereby the bowl is built one layer at a time (an additive process) before finally turning away the edges to form a final shape (a subtractive process).

A CNC mill operates on three axes, x, y, and z, a Cartesian coordinate system. In the Cartesian system, any point can be identified based on the three coordinates or the distance from a specified point.

The G-code will tell the CNC where to move the head. The code uses a simple syntax in the style of G1 x100 y100 (G=go, 1=slow speed, x direction 100 steps, y direction 100 steps).

Imagine building a 3D topographic map of Mount Rainier in Washington State. The normal process, called contour modeling, would be to take several topographic maps of Mount Rainier and glue them on to sheets of either plywood or cardboard. The maps are then cut out following individual contour lines at regular elevations.

The sections are stacked and glued in order, on a table, to form a 3D model of the mountain.

This process is used at many national parks to show items of interest and elevations. Architects use the method to show the land

Topography of Mount Rainier. Terrain2STL (Thatcher Chamberlin)/Google Maps 13

3D PRINTERS FOR WOODWORKERS

Mount Rainier model

around a building site. Model makers use similar methods to create models of parks and resorts.

Depending on the size of the model and the precision of the craftsman, the model can be a very accurate representation of a landscape, showing the terrain built one layer at a time. However, these models can be very time consuming to construct, and very expensive if accuracy is called for.

If we take the data for Mount Rainier and run it through a CAD/ CAM program, we can generate the same model using a CNC router.

The router will cut a block of wood, on a plane, one layer at a time. It removes the necessary material for that layer, then it moves down to the next layer and starts cutting again. The router will continue cutting down the block of wood until what remains is a model of Mount Rainier. How fine the representation is depends on the thickness of the layers. The layer lines can be left in place, or they can be removed, leaving a smooth contour line. The CNC will perform the same task 14

B asics of 3 D P rintin g

3D printing, layer by layer

as the model maker but much faster and with greater accuracy. The craftsman still has an important role to play as he goes from working with a coping saw to programming a design into the computer and setting up the CNC router.

The 3D printer works like the CNC router but in reverse, by adding material. Like the craftsman-built model, the printer will lay down layers of material to represent the contour lines. It will lay down one layer at a time on an x and y axis and then move up to the next layer, on the z axis, until the model is complete. Each layer is defined by the same data as with the CNC. The operator decides the accuracy of the print and the layer height. A model can be hollow or filled. You can design a model with an internal structure and place parts inside the model as it is built. You can have holes inside a printed part for captive nuts by pausing on a layer and installing the nuts. You then restart the printer to finish the part with the captive nut.

Because a 3D printer works by adding material layer by layer, designs can be made that can’t be manufactured using any other method. The Veritas P1169 3D-Printed Plumb Bob is a design that can only be made through additive manufacturing. Veritas made the plumb bob to show what could be accomplished using the new technology.

15

3D PRINTERS FOR WOODWORKERS

A 3D printing of Mount Rainer’s topography

There are very few industries that are not currently using some form of additive manufacturing. Dental offices have started printing crowns in the office, allowing a tooth to be replaced in one sitting instead of two weeks.

Four bridges have been constructed using additive manufacturing technologies: one in the Netherlands, one in Spain, and two in China. The one in the Netherlands was built in place using robots to splatter-weld the bridge from both ends, meeting in the middle.

The bridge in Spain was built using microfiber-reinforced concrete.

And the bridges in China were printed using ABS plastic and a more traditional but large (very large) FDM printer.

Children’s prostheses are currently a big use for 3D printers.

Prostheses are expensive, and kids continually grow out of them.

Several organizations are providing designs and information to owners of 3D printers, allowing them to make hands and arms for kids.

One of these organizations is e-Nable.

16

B asics of 3 D P rintin g

A Veritas 3D-printed plumb bob. Lee Valley Tools Ltd.

Jewelers have adopted 3D printing, especially with the use of stereolithography (SLA) printers. The resins used in SLA printers produce highly detailed prints that when placed in a furnace will burn without leaving ash. Prints from SLA printers work very well for lost-wax casting.

17

3D PRINTERS FOR WOODWORKERS

Dave Kindig and his team at custom-car shop Kindig-It Design use a 3D printer to create custom trim for their cars. The 3D printer gives their shop the ability to generate unique designs and builds. To create a special look, Dave and his team are able to use materials that are not typically found in cars.

Like CNC routers, 3D printers can make the craftsman’s job easier. More tools and jigs can be made from a combination of metal and plastic. Most of the plastic parts can be printed. In the future you will be able to go online for the tool or jig you need, buy it, download it, and print it. Tools like speed squares, pocket screw jigs, feather boards, and clamps can all be printed on a 3D printer and made available to your shop as needed.

18

Chapter 7

Filaments

There is a great future in plastics. —Mr. McGuire, The Graduate

F

ilaments are plastics that have been formed into threads of specific diameters ready to be fed into the 3D printer. Filaments can be made from different plastics, and will have different characteristics depending on the plastic. Four things to consider when choosing a filament are the plastic glass temperature (or glass transition zone), the tensile strength of the material, material durability, and the ease of printing.

The plastic glass temperature refers to the temperature where the plastic starts to soften. It tells you how heat tolerant the plastic is. ABS has a high glass temperature and can be used in cars or other areas that see high temperatures.

PLA has a low glass temperature, so parts made from PLA will not survive summer heat in a car.

Tensile strength indicates how much force the plastic can tolerate (or withstand). Will the part be placed under

3D PRINTERS FOR WOODWORKERS

Filament for 3D printers

a load? Nylons have a very high tensile strength. PLA, on the other hand, will deform under a load.

Durability or wear resistance is important for parts that are placed under constant use. A Lego will see very little wear use whereas a drawer or door handle can see quite a bit.

Ease of printing becomes one of the more important considerations for someone new to printing. PLA is one of the easiest filaments to print with. It has a low glass temperature and low tensile strength but doesn’t have great durability. However, it is very easy to print with and is cheap.

58

F ila m ents

In this chapter we will explore each of the most common types of filaments. The table below summarizes their main characteristics.

Table of Filament Properties (Strength, Durability, and Ease of Print Are Rated on a 5 Point Scale, with 5 Being the Best) ABS PLA PETG Nylon TPE Print tempera-

PC

Metal

230- 190- 230250 220 250

260300

250- 280270 300

depends

Soluble

ture (°C) Strength

4

3

4

NA

2

5

4

1

Durability 4

4

4

NA

3

5

4

1

Glass tempera-

105

60

88

70

50

110

depends

1

3

5

4

1

3

2

2

4

ture (°C) Ease of print

Acrylonitrile butadiene styrene (ABS) Strength 4 Durability 4 Glass temperature 3 Ease of print 3 When you think of ABS plastic, think of Legos, which are made of ABS. ABS is the grandfather of 3D printing filaments. It is easy to print with and is a strong, durable plastic. The glass transition temperature of ABS is about 105°C, so it is ideal for high-temperature uses, such as the inside of a car. ABS is an amalgamation of three different plastics, so each manufacturer has a slightly different formula for making their plastic. Not all formulas will work equally well on all printers or applications. By changing ABS manufacturers, you may find that one works better than others for your application.

59

3D PRINTERS FOR WOODWORKERS

The problem with ABS is that it tends to shrink as it cools down.

This can cause warpage of the prints. To prevent this, the printer requires a heated bed and an enclosed print area to print.

Polylactic acid (PLA) Strength 3 Durability 4 Glass temperature 2 Ease of print 5 Polylactic acid, or PLA plastic, is a thermal plastic made from corn. It is fully biodegradable to the point where it can be used as a temporary part in the human body, dissolving in about two years.

PLA is one of the most popular plastics in the 3D printing world.

Not only is it biodegradable and made from a renewable resource, but its print temperature is low and it doesn’t tend to warp like other plastics. The disadvantage of PLA is that it has low strength and tends to be brittle. PLA should not be used for projects that require impact resistance. PLA also has a low glass temperature, so it should not be used in environments where it will see high heat.

All manufacturers use just one resin to make PLA. Differences in filament color are due to the additives that manufacturers use.

Because of the lower print temperatures and the fact that it doesn’t warp, PLA can be printed easily on low-end printers that don’t have heated beds or enclosures.

Polyethylene terephthalate (PET or PETG) Strength 4 Durability 4 Glass temperature 4 Ease of print 4

60

F ila m ents

PET is a plastic, and is the most common type of polyester used commercially. The G in PETG indicates that ethylene glycol is used in its production. All PET used to make filaments uses ethylene glycol and is PETG regardless of whether the G is present or not.

PET is also known as polyester, and 70% of the PET manufactured is used in the textile industry. Most of the remaining 30% is used in the manufacture of various containers and bottles. More PET is used in the production of rugs and leisure suits than in the manufacture of water bottles and straws.

PET is a little more difficult to print with than PLA, but plate adhesion is very good and warpage is not an issue. PET is stronger and more flexible than either ABS or PLA so it has less tendency to break. Most PET filaments will print between 220째C and 250째C, with some printing up to 270째C. Most PET filaments have a glass transition temperature of 80째C, making them better for use in hot environments than PLA, although not as good as ABS. Companies modify their PET filaments to achieve different results. PET is foodgrade plastic. Some filaments have been developed for greater clarity, and there are PET filaments that can take higher temperatures.

Nylon Strength NA Durability NA Glass temperature 5 Ease of print 1 Nylon is a generic designation for a family of synthetic thermoplastics developed in the 1930s by the DuPont company. Nylon is engineered plastic that is both tough and flexible. It was originally used for toothbrush bristles. Unlike other thermoplastics, many of the available nylons are based on chemical processes specific to the manufacture of that particular nylon, each one developed to exhibit different characteristics. Kevlar is a nylon thermoplastic.

61

3D PRINTERS FOR WOODWORKERS

The attributes listed above for nylon vary, and depend on the type of nylon you are using. Most nylons have high strength and durability, but some can be very flexible. Their glass temperature is high.

Nylon can be found with a spectrum of properties. Nylon filaments can be designed to print in a wide range of temperatures, so you need to verify a specific filament’s print temperature before using it. Another factor is the varying amounts of carbon fibers in nylon filaments. The carbon can increase the strength and stiffness of the print. Nylon with carbon fiber can be as strong as aluminum.

A drawback to nylon is that it is difficult to get good adhesion on the build plate with it. Frequently, additives need to be used on the build plate, such as glue stick, to get the necessary adhesion. But one of the advantages of nylon is that it has good bonding between layers.

Thermoplastic elastomers (TPE) Strength 2 Durability 3 Glass temperature 3 Ease of print 3 Thermoplastic elastomers are plastics that will retain an elastic behavior after being formed into a part. TPE is not practical for most printing, but there are applications where it is very useful, such as on the jaws of a clamp or vice. TPE prints much better in printers where the extruder is connected directly to the hot end, rather than those that use a Bowden tube system.

Polycarbonate (PC) Strength 5 Durability 5 Glass temperature 4 Ease of print 2 62

F ila m ents

Polycarbonate filaments are the strongest, toughest 3D printing filaments available. The glass transition temperature for polycarbonate is around 110°C. PC requires a very high print temperature, with most running around 280°C to 300°C. Some have been formulated to print between 250°C and 270°C, making them more compatible with current 3D printers. When you are looking for strength, PC and nylon are the two best options.

Metal-based filaments Strength 4 Durability 4 Glass temperature 4 Ease of print 2 Like nylon, the attributes of the filament depend on the type of metal and the base plastic.

PLA filaments are available with added metal powders, including iron, copper, brass, and bronze. These filaments look like filler metal and can create some interesting effects, including the development of a patina on the project. A great use for metal-based filaments is creating faux metal fittings for embellishment of wood projects.

The problem with these filaments is that they are highly abrasive and can quickly erode a brass nozzle. Metal-based filaments should only be used only with a hardened steel nozzle.

Soluble/removable thermoplastics Strength 1 Durability 1 Glass temperature 1 Ease of print 4

63

3D PRINTERS FOR WOODWORKERS

These filaments are intended for support only. The only attributes required of them are that they are easy to print with and the supports are easy to remove.

Anytime you have an overhang greater than 45 degrees you will need supports. Most slicer programs will design and install supports when needed, using the material in the extruder. With a dual-head or multi-material printer you have the option of using filaments that are specifically designed to work as support material. For example, PolySupport is a filament designed to be easily removed from the project, and is particularly useful for hard-to-access areas. Unlike if you use the same material for supports that you do for the rest of the print, PolySupport can be removed leaving little scarring on the print.

Soluble filaments can provide support in areas of the project that are completely inaccessible. You can print a bearing using soluble filament as a support material. The support material will separate the components, allowing the bearing to be printed in one part. The support material can be dissolved leaving a functional bearing.

In addition to the filaments discussed above, new filaments are being developed that are stronger, tougher, less prone to warpage, and easier to print. And cheaper and more user-friendly variations of the common filaments already in use are always being introduced.

The most common and easiest to get started with is still PLA.

Filament Size 3D filaments come in two different sizes: 1.75 mm and 2.85 mm.

The 1.75 filament is the most popular size. Make sure you have the correct size for your printer.

64

Chapter 10

Print Projects

3D printing is already shaking our age-old notions of what can and can’t be made. But what we’ve seen so far is just the tip of the iceberg. The next episode of 3D printing will involve printing entirely new kinds of materials. Eventually we will print complete products—circuits, motors, and batteries already included. At that point, all bets are off.

—Hod Lipson, Director of Columbia University’s Creative Machines Lab

Y

ou have a 3D printer. You have it put together and it is working. The printer has been tested and calibrated.

Now what do you do with the printer? Here are some projects to help understand what the printer can do and how to get the most from your printer. The projects move from simple to complex, and will teach you important things such as how to orientate your project and when to use supports. They will also help develop your understanding of which filament will work best for each project and why. Let’s go make something!

3D PRINTERS FOR WOODWORKERS

Paint Points Paint points are used by woodworkers to hold up a project for painting, allowing for minimal contact with the part while applying paint.

Due to its design, the paint points project introduces new challenges for your printer and unique elements for your prints. The paint points’ walls are thin, their contact area with the bed is small, and the bottom of a paint point is curved. 3D printers don’t do well with overhangs of less than 45 degrees. They will bridge between two points, depending on the distance between the points. The bottoms of the paint points are curved at an angle much less than 45 degrees, testing your printer’s ability to print at a low angle. If the printer is having trouble with the angle and is leaving strings hanging below the curve, supports can be added. If supports are added in the slicer, the whole paint point will be supported, which is not the outcome you are looking for. The cure for this is to build supports into the design.

Paint points 82

P rint P ro j ects

Print the paint points using the following settings: File: www.thingiverse.com/thing:3536003 Material: PLA Temperature: 200°C or in accordance with the manufacturer’s directions Bed temperature: 60°C (if you have a heated bed) Infill: 20% Support: none Brim: not needed Raft: not needed

Paint points ready for use

83

3D PRINTERS FOR WOODWORKERS

Center Finders Center Finders for Dowels Center finders are used to quickly find the center of a dowel or block of wood by tracing a 45-degree angle across the wood. When printing the center finders for dowels project below, we need to be concerned about the placement of the part on the build plate. There are three flat sides to this project, but two of them have unsupported edges. If either of these two sides is placed on the build plate, without supports, the print will probably fail. Supports use material and cause waste, so we prefer to avoid using them unless necessary. We don’t want to use supports with this project, so we set the orientation on a plane that doesn’t have unsupported sides.

Center finder for dowels

This center finder is primarily designed for use with dowels and 2x square stock, but can be used for larger pieces.

Print the dowel center finder using the following settings:

84

P rint P ro j ects

File: www.thingiverse.com/thing:3536035 Material: PLA Temperature: 200°C or in accordance with the manufacturer’s directions for PLA Bed temperature: 60°C (if you have a heated bed) for PLA Infill: 20% Support: none Brim: not needed Raft: not needed

Center Finders for Bowl Stock This is a larger center finder that is primarily designed for use with round or square stock. The center is angled at 45 degrees. Most printers will print unsupported at this angle without sagging. The project can be printed in any one of the three orientations. The strength of a print will vary in different directions depending on the orientation of the layers. Think of the printed plastic as having a grain structure not unlike that of wood. On the whole, this is an important consideration in 3D printing, although it is not important in this project. One of the nice things about this design is that it can be modified with a company logo.

Print the center finder using the following settings: File: www.thingiverse.com/thing:3536035 Material: PLA Temperature: 200°C or in accordance with the manufacturer’s directions for PLA Bed temperature: 60°C (if you have a heated bed) for PLA Infill: 20% Support: none Brim: not needed Raft: not needed 85

3D PRINTERS FOR WOODWORKERS

Center finder for bowl stock

Center finders 86

P rint P ro j ects

Measuring Instruments

Bowl thickness calipers

3D-printed calipers 87

3D PRINTERS FOR WOODWORKERS

Print the calipers using the following settings: File: www.thingiverse.com/thing:3536043 Material: PLA Temperature: 200°C or in accordance with the manufacturer’s directions for PLA Bed temperature: 60°C (if you have a heated bed) for PLA Infill: 20% Support: none Brim: not needed Raft: not needed

Speed Square Print Adhesion I tend to keep two or three speed squares around the shop and am constantly looking for them. You can get a good speed square for $5, but with a 3D printer you can print one anytime you need it for $1. The speed square should be printed upright. Printing upright allows the speed square to have a full base, giving you a 45-degree angle in either direction. To accomplish this, you need good adhesion. The height of the speed square combined with the small base will give you a good indication of the adhesion you have on your build plate.

I find I get a little more strength if I use four perimeters and 40% infill. Not all slicer software will allow you to change the number of perimeters.

88

P rint P ro j ects

Printed speed square

Print the speed square using the following settings: File: www.thingiverse.com/thing:3536050 Material: PLA Temperature: 200 C or in accordance with the manufacturer’s directions for PLA Bed temperature: 60 C (if you have a heated bed) for PLA Infill: 40% Perimeters: 4 Support: none Brim: not needed Raft: not needed

89